Hundreds of Kenyans fled their homes on Sunday after 13 people were speared or stabbed to death north-west of Nairobi in tribal clashes over access to water, residents and officials said. Four were killed when they were pulled from vehicles at impromptu checkpoints set up by rival Kikuyu and Maasai groups which attacked anyone from the "wrong" tribe on the main road from Nairobi to the Maasai Mara safari park.
Saturday's violence was the latest in a series of clashes between members of various communities over land, an explosive issue President Mwai Kibaki's government says it will address.
National police spokesman Jaspher Ombati said the bloodshed killed 13 people in the Mai Mahiu area in the shadow of Mount Longonot volcano.
Maasai elders said their warriors intended to take revenge for those Maasais killed - believed to be at least six - by evicting as many Kikuyus from the area as possible.
Dozens of Maasai and Kikuyu fighters faced each other across the main road to the Maasai Mara in the late afternoon. The Kikuyus carried machetes, the Maasais were armed with spears, bows and arrows and metal-studded fighting sticks.
"You killed our people in our own land. We are going to evict you," sand the young red-robed Maasai warriors.
The fighting centres on disputes over access to water in the area, traditionally roamed by nomadic Maasai cattle herders but settled since the 1970s by small-scale farmers from the Kikuyu tribe.
"I used to be a wealthy man but all my wealth was reduced to ashes," said Johnston Kimujino, a Maasai in his mid 40s who said his thatched home had been burnt down in the violence.
"I have nowhere to go. I appeal to the government to assist me," Kimujino, clad in traditional red robes, said at a centre for the displaced where he had brought his 10 children and four wives.